American Racing Headers makes a shorty h-pipe to go with their longtubes. Not sure if they sell just the midpipe though. You may still have to modify it to go with your current longtubes anyway. Here's a link to what I'm talking about. You may be able to give ARH a call to see if the midpipe can be sold by itself.
American Racing Headers Long Tube Headers 1-3/4" With 2-1/2" Off-Road H-Pipe Stainless Steel V6 2011-2014
Sent from the future.
2012 Kona Blue 3.7L V6:
Borla LT headers, O/R h-pipe, Borla S-types, 3.73 gears,
Steeda adjustable UCA w/ mount, BMR LCAs, Airaid CAI,
LCA Relocation brackets, AE driveshaft, GT 80mm TB,
Black 18x9/10 2010 GT500 Wheels w/ Nitto NT555s,
Eibach Sportline Springs/shocks & Koni STR.T Struts